1. Field of the Invention
The present invention relates to an image processing device that corrects a fixed pattern noise as an isolated point, an image pickup apparatus, and an image processing method.
2. Description of the Related Art
For an image pickup apparatus that converts an optical image of an object formed by an optical system into electric signals, various techniques have been proposed for correcting a fixed pattern noise as an isolated point generated from the image pickup apparatus (hereafter, referred to as an FPN as appropriate), for example including the following methods.
(1) Technique to store the position of an FPN in advance and correct the FPN in the stored position.
(2) Technique to correct an FPN based on the difference value between two images.
(2A) Technique to acquire an FPN image in a state where an image pickup device is shielded and subtract the FPN image from a normal shooting image to correct an FPN.
(2B) Technique to acquire two images different in exposure time without shielding an image pickup device, and subtract a short-time exposure image from a long-time exposure image to correct an FPN (e.g., refer to Japanese Patent Application Laid-Open Publication No. 2011-228771).
(3) Technique to detect an FPN from data on a shot image itself and correct the FPN (e.g., refer to Japanese Patent Application Laid-Open Publication No. 2007-81704).